In playing with things, I created a slightly customized phpmyadmin.pl install script and added it to a /var/skel/installers directory.
I added the script through the Script Installers interface.

Unfortunately, because I named the file the same as the standard one in /usr/libexec/webmin/virtual-servers/scripts, this one replaces the original (not what I wanted, but I goofed).

So I'd like to start if over but don't know how to actually delete an script installer from the VM database.

So my question is: how do I delete the reference to my custom installer and let the system go back to normal?

Seems that if you:
1) Remove the new *.pl file
2) Add the standard /usr/libexec/webmin/virtual-servers/scripts/*.pl file back as a script installer that it replaces the installer script by the new one (assuming it overwrites the name since they're the same and then uses the standard info).